Paul Behrens (a leading environmental scientist) in his excellent book "The Best of Times, The Worst of Times" published in 2020, suggests that reducing meat consumption is probably "the single best individual step we can make for a liveable world"
As of 2017, there were around 1.5 billion cattle, 2 billion pigs and 1 billion sheep living on earth at any moment. Around 80% of all agricultural land is used to support livestock, and consumes one-third of the worlds abstracted water. 80% of Amazonian deforestation is to make way for cattle ranching. 80% of soy grown in the Amazon is for animal feed. Over a third of all crops goes to feeding animals.
To combat climate change, the global food system needs to change – not only are plant-based diets accompanied by a lower incidence of noncommunicable disease and other health benefits, but they are also better for the planet.
The global food system accounts for about 37 per cent of all greenhouse gas emissions and nearly one-quarter of the world’s total emissions. Reducing food loss and waste as well as transitioning to sustainable diets could have a significant impact on carbon dioxide (CO2) emissions, according to a report released from the United Nations, World Wildlife Fund, and Climate Focus. Dr Charlotte Streck, co-founder and director of Climate Focus said: “Food systems are a neglected mitigation opportunity and there is rarely any mitigation opportunity with so many sustainable benefits”.
The researchers identified sixteen ways in which policymakers can increase sustainability throughout the food production chain, including agricultural emissions, reducing food waste, and shifting to healthier, more sustainable diets, which they found may contribute up 20 per cent of the mitigation effort required to keep global temperature rise below the 1.5 degrees Celcius target by 2050.
A move to plant-based diets that are high in coarse grains, fruits, vegetables, nuts and seeds, while limiting meat intake to around 60 grams per person per day could reduce agricultural emissions by up to eight gigatons of carbon each year.
Another study published in Nature Sustainability found that a widespread dietary shift from meat to plant-based foods over the next few decades could remove as much as 16 years of global fossil-fuel CO2 emissions – which could essentially double the Earth’s rapidly diminishing carbon budget.
Plant-based proteins, like nuts, beans, and lentils, use only a portion of the land required to produce dairy and meat – while still providing essential nutrients. A shift to plant sources of protein would free up land that could be used to support beneficial ecosystems, such as native forests that absorb carbon dioxide.
Avoiding meat and dairy products is the single biggest way to reduce your environmental impact on the planet.
Additional information
Plant based diet can fight climate change:
https://www.bbc.co.uk/news/science-environment-49238749
Why we need policies to reduce meat consumption now:
https://www.vox.com/21562639/climate-change-plant-based-diets-science-meat-dairy
Can switching to a plant-based diet really save the planet?